Template overriding question

my company is developing a module that will be shipped with a default theme. For our clients we want to provide also a little set of other themes, but also we want to allow any client to customize its installation (without modify the theme).

At the moment themes override mysite. Like you found, there is discussion to change this but for now, you need to edit the theme or store you overrided templates in a subtheme like themes/xxxtheme_custom/.. which should? override themes/xxxtheme.

Anyhow this seems to me quite a big issue for Silverstripe and Theme/Module development, hope that release 3 will fix it.

UPDATE (little later) - yes, the subtheme can override a module, but you must call the subtheme like the theme plus _ (underscore) and the module's name (eg. theme/theme_module/). So is not really useful for my issue ;)